ENGLEWOOD, Colo. -- Wade Phillips, who has spent more than four decades as an assistant or head coach in the NFL, was once asked why it seemed like the road to the big headset -- the head coaching job -- seemed a little longer and a lot bumpier for those with defensive résumés.

"Sometimes the perception among the people hiring or talking about the hiring is that the guys on defense aren't as smart, and I don't think that's the case at all, by a long ways, but I think that's the way they think when they hire people sometimes," Phillips said.

When the Denver Broncos and New York Jets play Sunday (4:05 p.m. ET, CBS), there will be two defensive coaches in charge -- Denver's Vic Fangio and New York's Robert Saleh. Fangio was an NFL assistant for more than three decades before he got his chance to be a head coach, and Saleh, at 42, is now in his first season with the Jets.

The two spent one season together on the same staff -- with the Houston Texans in 2005 -- when Fangio was the defensive coordinator and Saleh was a coaching intern.

"We've remained in contact over the years," Fangio said this week. "When he was out in San Francisco, I would go out there often to visit and we played golf a couple times together, so yeah, we've remained in contact over the years."

"He's not much for words," said Saleh of Fango, "... But I took a lot from Vic -- he's one of the most detailed men I've ever been around. He's got tremendous conviction in his philosophy ... it's been a great ride and a pleasure to know him."

Fangio also said of their season together that Saleh had a "great work ethic and had a good feel for the game. You could tell he had a bright future as a coach."

But in a pass-happy league, the next big thing among offensive playcallers often has the inside track to become a head coach. Defensive assistants must often have a longer and more decorated résumé and must overcome the perception they do not embrace analytics or are not pushing the tactical envelope.

"I'm not going to pretend to know or understand what ownership is looking for when they're hiring people, I really don't," Pittsburgh Steelers coach Mike Tomlin said. "I know that defensive coaches and leaders are capable of leading football teams, and I think that's displayed week in and week out in stadiums, regardless of current climate."

Tomlin, now in his 15th season as Steelers coach, was a 34-year-old defensive coordinator for the Minnesota Vikings when the Steelers hired him in 2007. Bills coach Sean McDermott was a 42-year-old defensive coordinator for the Carolina Panthers when he was hired in Buffalo. But during this past offseason's hiring cycle, only two of the seven openings were filled by coaches with largely defensive backgrounds -- Saleh and former Broncos assistant Brandon Staley with the Los Angeles Chargers.

Overall, there are now 19 head coaches in the league with backgrounds largely on offense, 11 with backgrounds largely on defense and two former special teams coordinators. If you're keeping score: three current coaches with offensive backgrounds have won Super Bowls with their current teams (Andy Reid, Sean Payton and Bruce Arians), which is equaled by the coaches with defensive backgrounds (Bill Belichick and his six rings, Tomlin and Pete Carroll).

When asked if he thought it was still more difficult for defensive coaches to get the nod as head coaches, Fangio said: "That was the case for sure, but I think it's coming back [to closer to 50-50] a little bit ... I think it's coming back."

"Young defensive coaches will catch up," former Bengals coach and current Arizona State special advisor Marvin Lewis said. "They will adapt to how offenses are playing, how the rules go with that and get their opportunities."

Fangio is now in his third season with the Broncos, and the team's 2-0 start means for the first time during his tenure they will move into October not having to dig out of a hole. Broncos players say Fangio has kept his straight-to-the-point approach since taking over but they have seen changes, such as practice schedules, as he progresses on the job.

"If there's something, he'll address it right there in front of everyone," Broncos quarterback Teddy Bridgewater said. "You can't have pride or ego when it comes to Coach Fangio. I like the fact that he wants this team to be a tough football team. We grind."

Broncos safety Justin Simmons said: "Vic has such a strong defensive mind, and the way he sees the game is unparalleled. That's why you'll see different variations throughout the league of the defense, but Vic is not at the helm."